Photovoltaic (PV) cells, commonly known as solar cells, are well known devices for direct conversion of solar radiation into electrical energy. Generally, solar cells are fabricated on a semiconductor wafer or substrate using semiconductor processing techniques to form a p-n junction near a surface of the substrate. Solar radiation impinging on the surface of, and entering into, the substrate creates electron and hole pairs in the bulk of the substrate. The electron and hole pairs migrate to p-doped and n-doped regions in the substrate, thereby generating a voltage differential between the doped regions. The doped regions are connected to conductive regions on the solar cell to direct an electrical current from the cell to an external circuit coupled thereto. A plurality of photovoltaic cells may be included in a solar module. A string of several to many solar modules may make up a solar system.
A challenge with PV systems mounted on roofs is that a PV system is a power source which may not have the ability to be turned off in the case of a fire. Such a situation may increase the hazard of fighting a fire on a residence which has a PV system. If each module can be turned off when the main power to the house is turned off by the fire fighters, then any electrical hazard may be greatly reduced. Specifically, the electrical hazard may be reduced to only the output of an individual module. However, challenges arise in providing a system with a reduced electrical hazard in a way that does not add significant cost to the PV system, and does not reduce the reliability of the PV system. Approaches attempted thus far are expensive and may have a negative impact on system reliability.